Muzzle loading grease gun



June 11, 1935- s. J. KRMQIMK MUZZLE LOADING GREASE GUN K Filed oct. 21,1931 ya M m w N Z m www mv n N ,m WNNN M w QQ mv e@ L 5 m n E m m w mm,mm. am WM. N E xv Sv um, NNY Nw NN mmv @www N MN w@ N Sn Nw mw will KwNN tlwwmkv I II n QN HN \WN Mw Ww QW N 6v@ s Patented June 11, 1935MUvzzLE LoAniNG ,GREASE GUN` Y Steven J. Krannak, Minneapolis", Minn.;assignor 'to l'vIin-A-Max Co., MinneapoliaMinn., a corporationoflvlinnescta Y' Application october 21,

1931, serial Nb. 570,078

2 Claims. (Cl. 221447.23)

' My invention provides a'highly ecient grease gun capable of'delivering grease" under' high pressure and being quickly reloaded withgrease. The grease container or barrel is provided with 5. means wherebyit may be quickly reloaded through its muzzle or discharge end; andhence this grease gun is herein designated as a muzzle loading greasegun, to distinguish it from other grease guns such as those disclosedand broadly claimed in prior patents issued to` V. A. vBoker, the oneNo. ,1,801,069 of April 14,1931,

and the other No. 1,803,3i2, of May 5, 1931.

Generally stated, the invention consists of the novel devices,combinations of dewices andar- RV rangement of parts hereinafterdescribed and defined in the claims.

Referring to the drawing, which illustrates the invention, whereinV likecharacters indicate like;

parts throughout the several views:- Fig. 1 is a vertical axial sectiontakenithrough the complete grease gun, some parts being shown in full;

Fig. 2 is an enlarged vertical section taken axially through the llingnozzle of the barrel or grease container of the gun and showing also insection the grease discharge nozzleV of a source of. grease supply suchas a large tank in which the grease is contained under pressure;

' Fig. 3 is a detail in section taken on the line 4 4 ofFg.1;and r Fig.4 is a detail in section take-non the line 3 3 of Fig. l.

The ejector portion of the grease gun is in the form of a differentialcylinder vand differential piston, in which the Vrelatively very smallplunger or stem of the piston works in the small greaseejectingcylinder, and wherein the large piston head is actuated by air pressure.The large cylinder 5 is axially aligned with and rigidly connected tothe relatively very small gun cylinder 5. The large piston 'I works Vinthe large cylinder 5 and its relatively very small plunger or stem 8works in the, small gun cylinder 6. A cylinder head 9 isboltedor'otherwise rigidly secured to the outer end ofc'ylinder 5 and isformed with air ports I, II, and I2 and with a valve head chamber I3,the lower en d of which isnormally closed by a screw-threaded plug Ill.

A tubular valve stem l5 works through the top of the cylinder casting 8and ata point below the contracted upper portion `oi the iv alvef,chamber I4 is formed with a valve head. i6, which when raised; cuts` offcommunication between ports l0 and I I, but Ywh ich,-whendepressedjopensnp 55. communication between said ports. Valve stern I5is 'provided with `upper lateral ports I 'Ifand lower ports i8.. Tovtheextreme uppervendv ofV valve stem Iis secured a capv I9 that looselyritsrv over the. hub 2G that surroundsthe upperportion'A of said steml5. This cap isyprovided with a 5 gasket 2 I which, when the cap andstem arede-l pressed, is tightly V'seated against the hub*y 2G. Theoperation of this ,valvev will be considered lateron. f' `ThecylindersiY and 6 arev rigidly secured re-A spectively lby columns 22-and 23 tothe bottom of the cylindricalw grease container .-or barrel 24.Column 22 is tubularso that it affordsl communication between thedelivery end of grease-cone taining barrel 2"and the bore of smallcylinder 6.v Working in the-barrel 2li is a follower-.acting pistonv 25.To the rear en d of barrel 24-is rigidly secured a cylinder head 26. Anair pipe 21 connects the port l2V ofcylinder head 9 to ports 28 and 29of cylinder head 2li. AV check valve, shown as'inthe form of a ball 30,rests on the upper end of pipe 2l and checks the flow from port v28backward into pipe 2'l. The port V29 is normally closedAV bya valve -3Iwhich, as shown.: is of .ball type, andfisv pressed againstr its seat byits screw, 32.applied through the topgof the head 26. The numeral 33indicates a nipple screwed into the head' and leading to the port I0thereof, 4This nipple 33, in practice, will be connected by a flexiblepipe or hose 34 to a source of air supply under pressure such as acompressed air tank. Y Y, l i

,The gun barrelv 6, at its delivery end, is enlarged to form ka recess6a to receive a check'valve 35 shown as in the form of a ball thatpermits 'a liow of grease from barrel vIi under pressure, vbut checks abackward flow. The coupling nipple 36 is screwed into the large cavityIia of thebarrel 6 and is connected to a flexible grease delivery pipe.or hose A37. A small oil return duct 38 leads from the recess la outwardof the valve 35 back into the conduit of the tubular column22. Thisconduit isinoi1` mally closed by a valve 39, shown as in the formi of aball that is tightly seated by a screw 401 VA finger-operatedValve-actuatingy lever 4I is. pivoted to the column 23 .with its shortend rest# ing; on the cap I 9. The long endi'o'f'this lever lll isshownas guided againstA lateral movements" but free' forfyerticalmovements by flangesj42v on the column 22, and its backturned free endstands in position to be engaged by a linger off a` handholdin'g thegrease gun by gripping of-barrel' 2,4f'in the space between the columnsv22 `an `zl232-- f To the front! or muzzle end of'the barrel 24 isVsecured a head 43 into which i'sftightlyf screwed sof the threadedtubular end of'a valve casing 44, which, near its threaded outer end,isprovided with an inwardly projecting annularstop flange 45. A thimble 46is screwed into the outer end of valve casing 44 and against theflange45. Working slidably through the thimble 46 is arvalveactingnozzle 41 and onto the end of the latter is screwed the tubular nozzletip 48. This nozzle Ytip 48 may be variously formedbut,V as shown,

is internally rthreaded and provided with an internally beveled rim 49.Y The nozzle 41 is tubular except at its inner end,

'which is left solid and is providedwith a diametrical port 5G that isnormallyclosed by the thimble 46. The solid inner end ofnozzle41isprovided` with an outstanding annular fiange that; is'Vnormally seated against the fiange 45 by a .coiled Y spring 52compressed between said vflange 5I and thebase of casing 44. fj

In Fig. v2, the numeral 53 indicate Vpart of a grease-containingtankinwhich grease will be maintained vunderA considerable pressure. Asshown, this tank is provided with an internally threaded greasedischarge tube 54, into which is screwed the tubular externally threadedstem of a valve casing 55; the outer end of which is closed byscrew-threadedfplug 56. A tubular grease discharge nozzle 51Yworks-slidably through the plug 56 and is springpressed forward byacoiled spring 58,:4 compressed between the .inner end of the sameandthebase of valve casing 55. The extreme outer end of this tubularnozzle 51 isfconically bevelledvv so as to closely fit the internally fkbevelled surface 49 of the nozzle tip 48. The extreme inner end ofnozzle 51 is closed butitsaxial passage is provided with adiametricalport 59V located just infront of anoutstanding annular fiangeformed Von thesolid inner end portion of said nozzle. As shown, a gasket6I is seated against the vinner .end of the plug 6|);V Normally spring58-woul`d press nozzle 51 outward to its limit',*w`itlf its flangeIIlseatedagainst the gasket Sian-d with its port 59 closed by the plug 56.Y

A quite heavy coiled Vspring 62 is located in the large cylinder 5 andits reduced extension` reacts against therbase of said extension yandagainst piston 1, and yieldinglyf'holds the sameand'the plunger 8retracted as shown in'Fig. 1. f

' Y Operation Normally, valve to its 1imit,- thereby cutting olicommunication between the air supply portIU and the inlet port Il tothelarge cylinder 5; and at'such time, the rearend: of large cylinder 5will be open to the atmosphere through the tubular valve stem I5 andits-ports I1 and I8. When the free end of lever .4I is raised, valvehead I6 and its stem I5 will be moved downward as shown in Fig.1,-thereby closing upper ports I1 and cutting-off the cylinder 5 fromcommunication withthe atmosphere, butopening the supply of compressedair from port ID around stem .I5 and through port `I I, to saidcylinder5and'through port '12, kand pipe 21 and port 28 to the rear end ofgreasecontaining barrel 24. Normally, of course, the A valve acting endof thenozzle 21 will close the' discharge `end of.barrel24 against thedischarge of greasethrough said nozzle 41.. When air is admitted yintherear end of cylinder 5 and .to the reargend of barrel 24, air will beadmitted into the latter, which will cause forward movementof thefollower piston 25, .therebyv keeping the grease in barrel V24.under-,pressure and cause the i Seme i9. 119W through thetubular commu2,2 into;

head I6v will be pressedupward' f1.1In agrease guna provided at one endwith a grease inlet and at the small gun barrelor cylinder that is infront of plunger 8, and by the said air pressure admitted into cylinder5, large piston 1 will be forced forward, causing plunger 8 to eject thegrease from gun barrel 6 under very high pressure.` Obviously, thedifference in cross-sectional area of piston 1 that comparatively lowair pressure on the latter will produce a veryhigh pressure per squareinchon thegreasein the gun barrel 6.

Each time the lever 4I is raised as above described, one grease-ejectingimpulse willbe imparted to plunger 8 and a step of forward movement willbe Ygiven the follower piston 25. Check valve 30 maintains the pressurein the rear end of barrel `24* when therear end of cylinder 5 is beingopen to thel atmosphere to permit return of piston' 1 under theaction'of spring 62.

When grease delivery pipe 31 is connected to a' receiving nipple, afteraV grease-delivery operation; the pressure' in the pipe 31 will be veryhigh so that withfsome types ofY nipples andadapters or couplers, therelease of the latter from theformer will be difficult. Thishowevenisma'del barrel 24 may be very quickly accomplished withthe device shownand describedand by anr opera-- tion Villustrated in Fig. 2, and whichis as follows:`

The nozzle tip of the grease gun is engaged with and then pressedragainst the projecting end of nozzle 51 under sufficient pressure toopen the port 5|)k of rgrease-receiving nozzle and to open'r the port 59of grease supply nozzle. These nozle port-opening sections will,ofcourse, be produced by compression of springs 52 and V58, Vto permita, displacement of air back of the followeracting piston'25 so that saidpiston will be moved' Y fromthe vfrontJbackto VYthe -rear of thegreasecontaining barrelz24, valve 3| must first be opened by releasingof screw 32, and under pressure fromf the supply tank 53, the greasewill be forced into the-barrel 24, causing the backward `movement offpiston 25 and complete fillingof the barrel 24 Vwithgrease.` When thisfilling has been accomplishedvalve 3|- should then be, again forced toits seat by screw 32, so as to close port 29.

In practice, the supply nozzle from the supply tank will advisably belocated where it is close to or` accessible from the place where thegrease gun would be used in greasing of carsl and the like. .This makesit1possible by the simplest kind of an action above described, to almostinstantly refill the grease-containing barrel of the grease gun. Notonly can the refilling of the grease gun be Very quickly" accomplished,v,but the discharge of grease for lubricating purposes by the means ofthe'grease-ejecting mechanism of the gun is made an easy matter, andpositive delivery of greaserun'der highpressure is insured. From whathas beenjsaid,V it is .obvious that various alterations Aand#changes indetails of constructionmayv befmade within the scope of the inventionherein disclosed'and broadly claimed. WhatI I ,claim'fisrgrease-containing lbarrel its opposite end with an air inlet passage andbetweenjsaidtwo noted passages a grease-outlet passage, a-normallyclosed valve in said grease intake passagefhaving a. projectingnozzle which, when pressed toward the interior of the barrel, openssaidfgrease intake valve, a rvalve in Vsaid airintake passage arrangedto be openedl bv pressure toward the interior of said barrel, aV oatingpiston working in said barrel between said air intake port and saidgrease outlet passage, means for controlling the discharge of greasefrom said grease-discharge passage, and means for releasing the airpressure in said barrel between said piston and said air intake valve,so that said piston may be retracted when grease pressure is applied tosaid barrel past the pressure-opened intake valve of said grease intakepassage.

2. In a grease gun, a grease-containing barrel provided at one end witha grease inlet and at its oppdsite end with an air inlet passage andbetween said two noted passages a grease-outlet passage, a normallyclosed valve in said grease intake passage having a projecting nozzlewhich,

when pressed toward the4 interior of the barrel, opens said greaseintake valve, a valve in said air intake passage arranged to be openedby pressure toward the interior of said barrel, a iloating pistonworking insaid barrel between said air intake port and said greaseoutlet passage, means for controlling the discharge of grease from saidgrease-discharge passage, comprisinga normallr closed outwardly openingcheck valve, and means Y for releasing the air pressure in said barrelbetween said piston and said air intake valve, so that said piston maybe retracted when grease pressure is applied to said barrel past thepressure-opened intake valve of said grease intake passage.

STEVEN J. KRANNAK.

